U.S. patent number 11,086,030 [Application Number 16/512,929] was granted by the patent office on 2021-08-10 for radiation imaging apparatus, manufacturing method thereof, and radiation imaging system.
This patent grant is currently assigned to CANON KABUSHIKI KAISHA. The grantee listed for this patent is CANON KABUSHIKI KAISHA. Invention is credited to Tomohiro Hoshina, Takamasa Ishii, Kota Nishibe.
United States Patent |
11,086,030 |
Nishibe , et al. |
August 10, 2021 |
Radiation imaging apparatus, manufacturing method thereof, and
radiation imaging system
Abstract
A radiation imaging apparatus includes a sensor base, a sensor
array that includes a plurality of sensor chips arranged in an
array, and in which three or more sensor chips out of the plurality
of sensor chips are arranged in one row of the sensor array, a
scintillator positioned on a side opposite to the sensor base with
respect to the sensor array, a bonding member that bonds the sensor
array and the scintillator, and a plurality of bonding sheets that
are separated from each other and bond the sensor base and the
plurality of sensor chips. Two adjacent sensor chips out of the
three or more sensor chips are bonded to the sensor base using
separate bonding sheets out of the plurality of bonding sheets.
Inventors: |
Nishibe; Kota (Kawasaki,
JP), Ishii; Takamasa (Honjo, JP), Hoshina;
Tomohiro (Kawasaki, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
CANON KABUSHIKI KAISHA |
Tokyo |
N/A |
JP |
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Assignee: |
CANON KABUSHIKI KAISHA (Tokyo,
JP)
|
Family
ID: |
67220721 |
Appl.
No.: |
16/512,929 |
Filed: |
July 16, 2019 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20200025953 A1 |
Jan 23, 2020 |
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Foreign Application Priority Data
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Jul 23, 2018 [JP] |
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JP2018-138015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01T
1/2928 (20130101); H01L 27/14663 (20130101); G01T
1/2018 (20130101); H01L 31/18 (20130101); H01L
25/042 (20130101) |
Current International
Class: |
G01T
1/20 (20060101); H01L 31/18 (20060101); G01T
1/29 (20060101); H01L 25/04 (20140101) |
Field of
Search: |
;250/370.11 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2006-278877 |
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Oct 2006 |
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JP |
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2012-145474 |
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Aug 2012 |
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JP |
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2014-106201 |
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Jun 2014 |
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JP |
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2015-114268 |
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Jun 2015 |
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JP |
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2016-118506 |
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Jun 2016 |
|
JP |
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2011/161897 |
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Dec 2011 |
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WO |
|
Primary Examiner: Porta; David P
Assistant Examiner: Gutierrez; Gisselle M
Attorney, Agent or Firm: Venable LLP
Claims
What is claimed is:
1. A radiation imaging apparatus, comprising: a sensor base; a
sensor array that includes a plurality of sensor chips arranged in
an array, and in which three or more sensor chips of the plurality
of sensor chips are arranged in one row of the sensor array; a
scintillator positioned on a side opposite to the sensor base with
respect to the sensor array; a bonding member that bonds the sensor
array and the scintillator: and a plurality of bonding sheets that
are separated from each other and bond the sensor base and the
plurality of sensor chips wherein two adjacent sensor chips out of
the three or more sensor chips are bonded to the sensor base using
separate bonding sheets out of the plurality of bonding sheets, at
least some sensor chips of the plurality of sensor chips have a
side on which a wiring member is arranged and on the side on which
the member is arranged, the bonding sheet extends beyond the side
to the outside of the sensor chip.
2. The radiation imaging apparatus according to claim 1, wherein a
first sensor chip and a second sensor chip from an end of the
sensor array are bonded to the sensor base using separate bonding
sheets in each row in the sensor array.
3. The radiation imaging apparatus according to claim 2, wherein
the second sensor chip and a third sensor chip from the end of the
sensor array are bonded to the sensor base using separate bonding
sheets in each row in the sensor array.
4. The radiation imaging apparatus according to claim 1, wherein
two adjacent sensor chips are bonded to the sensor base using
separate bonding sheets in an entire region of the sensor
array.
5. The radiation imaging apparatus according to claim 1, wherein
the plurality of sensor chips correspond one-to-one with the
plurality of bonding sheets.
6. The radiation imaging apparatus according to claim 1, wherein
each of the plurality of sensor chips is shaped as a rectangle, and
among sides of a sensor chip bonded to the sensor base using a
bonding sheet that is separate from a bonding sheet of the adjacent
sensor chip, on a side facing an adjacent sensor chip an outer
periphery of the bonding sheet is positioned inward of the side
facing the adjacent sensor chip.
7. The radiation imaging apparatus according claim 1, wherein at
least some sensor chips of the plurality of sensor chips have a
side on which a wiring member is arranged the bonding sheets are
tape comprising a cushioning core material with adhesive material
applied to two opposing sides, and among two shorter sides of the
sensor chip, the side on which the wiring member is arranged is
directed towards the outside of the sensor array.
8. The radiation imaging apparatus according to claim 1, wherein
the bonding member has a property of exhibiting adhesion force when
heated.
9. A radiation imaging system, comprising: the radiation imaging
apparatus according to claim 1; and a processing unit configured to
process a signal acquired by the radiation imaging apparatus.
10. A method for manufacturing a radiation imaging apparatus,
comprising the steps of: forming a sensor panel by banding a
plurality of sensor chips to a sensor base using a plurality of
bonding sheets separated from each other, such that three or more
sensor chips of the plurality of sensor chips are arranged in one
row of a sensor array in which the plurality of sensor chips are
arranged in an array; and bonding, the sensor panel and a
scintillator using a bonding member such that the scintillator is
positioned on a side opposite to the sensor base with respect to
the sensor array, wherein at least some sensor chips of the
plurality of sensor chips have a side on which a wiring is
arranged, and forming the sensor panel includes bonding two
adjacent sensor chips out of the three or more sensor chips to the
sensor base using separate bonding sheets of the plurality of
bonding sheets.
11. The method according to claim 10, wherein the scintillator and
the sensor array are bonded through heat pressure bonding.
Description
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a radiation imaging apparatus, a
manufacturing method thereof, and a radiation imaging system.
Description of the Related Art
There are known radiation imaging apparatuses called indirect-type
radiation imaging apparatuses, in which incident radiation is
converted into visible light by a scintillator, and the visible
light is converted into electrical signals by photoelectric
conversion elements of a sensor panel. Manufacturing methods of
such indirect-type radiation imaging apparatuses include a method
for directly forming a scintillator on a sensor panel (direct
formation method), and a method for separately manufacturing a
sensor panel and a scintillator panel, and adhering them to each
other (indirect formation method). Japanese Patent Laid-Open No.
2015-114268 describes constituting a sensor panel by arranging a
plurality of sensor chips in an array when forming a radiation
imaging apparatus through the indirect formation method.
SUMMARY OF THE INVENTION
When manufacturing a radiation imaging apparatus in which a
plurality of sensor chips constitute a sensor panel, through an
indirect formation method, there have been cases where the sensor
chips are shifted from their positions as designed. The present
inventors have found that this is due to a bonding sheet, which
bonds a base and the plurality of sensor chips to each other,
entering the spaces between the sensor chips as a result of the
scintillator panel being pressed against the sensor panel. An
aspect of the present invention provides a technique for reducing
positional shifts of the plurality of sensor chips that constitute
the sensor panel.
According to some embodiments, a radiation imaging apparatus
comprising: a sensor base; a sensor array that includes a plurality
of sensor chips arranged in an array, and in which three or more
sensor chips out of the plurality of sensor chips are arranged in
one row of the sensor array; a scintillator positioned on a side
opposite to the sensor base with respect to the sensor array; a
bonding member that bonds the sensor array and the scintillator;
and a plurality of bonding sheets that are separated from each
other and bond the sensor base and the plurality of sensor chips,
wherein two adjacent sensor chips out of the three or more sensor
chips are bonded to the sensor base using separate bonding sheets
out of the plurality of bonding sheets is provided.
Further features of the present invention will become apparent from
the following description of exemplary embodiments with reference
to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1C are diagrams illustrating a configuration example of
a radiation imaging apparatus according to a first embodiment.
FIGS. 2A and 2B are diagrams illustrating the configuration of a
radiation imaging apparatus according to a comparison example.
FIGS. 3A to 3C are diagrams illustrating a configuration example of
a radiation imaging apparatus according to a second embodiment.
FIGS. 4A to 4C are diagrams illustrating a configuration example of
a radiation imaging apparatus according to a third embodiment.
FIGS. 5A to 5C are diagrams illustrating a configuration example of
a radiation imaging apparatus according to a fourth embodiment.
FIGS. 6A to 6C are diagrams illustrating a configuration example of
a radiation imaging apparatus according to a fifth embodiment.
FIGS. 7A to 7C are diagrams illustrating a configuration example of
a radiation imaging apparatus according to a sixth embodiment.
FIG. 8 is a diagram illustrating a configuration example of a
radiation imaging system according to another embodiment.
DESCRIPTION OF THE EMBODIMENTS
Embodiments of the present invention will be described below with
reference to the accompanying drawings. Throughout various
embodiments, the same reference signs are assigned to similar
constituent elements, and overlapping description is omitted. In
addition, the embodiments can be changed and combined as
appropriate. Description will be given below on the embodiments of
the present invention in a context of a radiation imaging apparatus
that is used for a medical imaging diagnostic apparatus, an
analysis apparatus, and the like. In the present specification,
light includes visible light and infrared rays, and radiation
includes X-rays, .alpha.-rays, .beta.-rays, and .gamma.-rays.
First Embodiment
A configuration example of a radiation imaging apparatus 100
according to a first embodiment will be described with reference to
FIGS. 1A to 1C. FIG. 1A is a plan view of the radiation imaging
apparatus 100. FIG. 1B is a cross-sectional view cut along a line
A-A' in FIG. 1A. FIG. 1C is a cross-sectional view cut along a line
B-B' in FIG. 1A. In FIG. 1A, for convenience of description, a
bonding member 104, a scintillator layer 105, and a scintillator
base 106 are omitted.
The radiation imaging apparatus 100 in particular has a sensor base
101, a plurality of bonding sheets 102, a plurality of sensor chips
103, the bonding member 104, the scintillator layer 105, and the
scintillator base 106. A specific bonding sheet 102 among the
plurality of bonding sheets 102 is referred to using a suffix such
as "bonding sheet 102a". A specific sensor chip 103 among the
plurality of sensor chips 103 is referred to by using a suffix such
as "sensor chip 103a". Radiation that has passed through a subject
such as a patient passes through the scintillator base 106, and is
converted into visible light by the scintillator layer 105. These
visible light is converted into electrical signals by photoelectric
conversion elements included in the plurality of sensor chips
103.
The plurality of sensor chips 103 are arranged in an array. The
plurality of sensor chips 103 arranged in an array constitute a
sensor array. In the sensor array, a direction along a line B-B' is
referred to as a row direction, and a direction along a line A-A'
is referred to as a column direction. In the example in FIG. 1A,
the plurality of sensor chips 103 are arranged in two rows and
eight columns, but there is no limitation to this. Each row of the
sensor array includes three or more sensor chips 103. The plurality
of sensor chips 103 are each shaped as a rectangle. A sensor chip
103 may be, for example, a CMOS sensor in which crystalline silicon
is used, or a PIN-type sensor or a MIS-type sensor in which
non-crystalline silicon is used. In each sensor chip 103, a
plurality of pixel circuits are arranged in an array. Each pixel
circuit includes a photoelectric conversion element, a transistor,
and the like. The configuration of a sensor chip 103 may be that of
an existing sensor chip, and thus a detailed description thereof is
omitted.
The plurality of sensor chips 103 are bonded to the sensor base 101
using the plurality of bonding sheets 102. The plurality of bonding
sheets 102 are separated from each other. In order to flatten the
upper faces, in other words the faces of the plurality of sensor
chips 103 that are in contact with the scintillator layer 105, the
bonding sheets 102 may have cushioning properties. For example, a
tape in which an adhesive material is applied to the two sides of a
cushioning core material may be used as a bonding sheet 102. The
core material may be formed of, for example, polyolefin-based
resin, polyester, nonwoven fabric, chemical fiber, a wire woven in
a lattice shape, or the like. Polystyrene resin that has a
relatively high flexibility may be used as the polyolefin-based
resin. For example, a metal wire or a resin wire may be used as the
wire. For example, at least one of acrylic adhesive, epoxy
adhesive, rubber-based adhesive, polyester-based adhesive,
polyamide-based adhesive, vinyl alkyl ether-based adhesive, and/or
silicone-based adhesive may be used as the adhesive material. From
the viewpoint of the flatness and the thermal expansion
coefficient, a metal, ceramics, glass, or a carbon material may be
used as the material of the sensor base 101.
The scintillator layer 105 is attached to the scintillator base
106. The scintillator layer 105 and the scintillator base 106
constitute the scintillator panel. For example, CFRP, amorphous
carbon, glass, or a metal (e.g., aluminum) is used as the material
of the scintillator base 106.
The scintillator layer 105 may be a group of granulous
scintillators, or a group of columnar scintillators. For example,
oxysulfide gadolinium (Gd.sub.2O.sub.2S:Tb) containing a minute
amount of terbium (Tb) is used as the granulous scintillators. For
example, CsI:Tl, CsI:Na, CsBr:Tl, NaI:Tl, LiI:Eu, or KI:Tl is used
as the columnar scintillators. If the scintillator layer 105
contains a halogen, the entire scintillator layer 105 may also be
covered with a moisture-resistant film in order to prevent
deterioration in performance due to humidity. The scintillator
panel may also have, between the scintillator layer 105 and the
scintillator base 106, a reflection layer for improving the
luminance, or may also have an absorption layer for improving the
MTF. The reflection layer may be formed of a metal such as Al or
Ag, or may be formed of light-reflecting pigment containing
TiO.sub.2 or SrO. The absorption layer may be formed of a material
such as black PET. The scintillator panel is positioned on the
opposite side to the sensor base 101 with respect to the sensor
array.
The sensor array and the scintillator panel are bonded using the
bonding member 104. Specifically, the plurality of sensor chips 103
(the face on the opposite side to the sensor base 101) and the
scintillator layer 105 (the face on the opposite side to the
scintillator base 106) are bonded. The bonding member 104 is, for
example, an adhesive sheet. Visible light passes through the
bonding member 104, and reaches the sensor chips 103. The bonding
member 104 may have a high transmissivity from the viewpoint of
luminance, and may be thin from the viewpoint of the MTF. There are
cases where a large crystal is generated while the scintillator is
being formed, and the flatness of the surface of the scintillator
is lost, depending on the type of the scintillator layer 105. When
a large crystal is pressed against a sensor chip 103, there is a
risk that the sensor chip 103 is damaged, and air bubbles are
generated. In view of this, the bonding member 104 may have a
thickness that is sufficient for covering the height of the large
crystal. From the viewpoint of handling air bubbles and securing
the MTF, the bonding member 104 may also have a thickness of about
10 to 100 The transmissivity of the bonding member 104 may be 80%
or higher. An OCA film used for a liquid crystal display and the
like may be used as the bonding member 104.
In the radiation imaging apparatus 100, 16 sensor chips 103 are
bonded to the sensor base 101 using five bonding sheets 102. A
sensor chip 103a is bonded to the sensor base 101 using a bonding
sheet 102a only. The bonding sheet 102a is used only for bonding of
the sensor chip 103a, and is not used for bonding of another sensor
chip 103. A bonding sheet 102b is used for bonding of twelve sensor
chips 103.
In each row in the sensor array, a first sensor chip 103 and a
second sensor chip 103 from each end of the sensor array are bonded
to the sensor base 101 using separate bonding sheets 102.
Specifically, the first sensor chip 103a from an end of the sensor
array is bonded using the bonding sheet 102a, and a second sensor
chip 103b from the end of the sensor array is bonded using the
bonding sheet 102b. In addition, two adjacent sensor chips 103 that
are on an end of the respective rows in the sensor array, are also
bonded to the sensor base 101 using separate bonding sheets 102.
Specifically, in a row, the first sensor chip 103a from the end of
the sensor array is bonded using the bonding sheet 102a, and, in
the other row, a first sensor chip 103e from the end of the sensor
array is bonded using a bonding sheet 102d.
Next, a manufacturing method of the radiation imaging apparatus 100
will be described. First, the above-described sensor panel and
scintillator panel are formed individually. The sensor panel is
formed by bonding the plurality of sensor chips 103 to the sensor
base using the plurality of bonding sheets 102 separated from each
other, such that the plurality of sensor chips 103 constitute the
sensor array. First, the plurality of bonding sheets 102 are
adhered onto the sensor base 101. Adhering of the bonding sheets
102 may be adhering using a hand roller, adhering using a dedicated
apparatus, or the like. Next, the plurality of sensor chips 103 are
aligned at equal intervals on the plurality of bonding sheets 102
so as to achieve the arrangement shown in FIG. 1A (i.e. tiling is
performed).
The scintillator panel is formed by attaching the scintillator
layer 105 to the scintillator base 106 (for example, through vapor
deposition). When forming a reflection layer between the
scintillator layer 105 and the scintillator base 106, a metal layer
made of Al, Ag, or the like may also be formed on the surface of
the scintillator base 106 through sputtering, and light-reflecting
pigment containing TiO.sub.2, SrO, or the like may be applied.
Subsequently, the sensor panel and the scintillator panel are
bonded using the bonding member 104. First, the bonding member 104
(e.g., an adhesive sheet) is adhered over the scintillator layer
105. If the bonding member 104 can be adhered to the scintillator
layer 105 at room temperature, the bonding member 104 can be
adhered to the scintillator layer 105 using a hand roller, a
laminating machine, or the like. Subsequently, the sensor panel is
adhered to a face on the opposite side to this bonding member 104.
The sensor panel is also adhered in a similar manner using a hand
roller, a laminating machine, or the like. The radiation imaging
apparatus 100 is manufactured through the above-described
processes.
A radiation imaging apparatus 200 according to a comparison example
will be described with reference to FIGS. 2A and 2B. The radiation
imaging apparatus 200 is different from the radiation imaging
apparatus 100 in that only one bonding sheet 102 is provided, and
may be similar to the radiation imaging apparatus 100 in other
respects. FIG. 2A is a cross-sectional view of the radiation
imaging apparatus 200 at a position corresponding to FIG. 1B. The
radiation imaging apparatus 200 is also manufactured by adhering a
sensor panel and a scintillator panel to each other. During this
adhering process, a plurality of sensor chips 103 are pressed
toward a sensor base 101. As a result, a portion of a bonding sheet
102 enters a space between two adjacent sensor chips 103. For
example, as shown in FIG. 2A, a portion 201 of the bonding sheet
102 enters the space between a sensor chip 103f and a sensor chip
103g. Due to this, the space between the two adjacent sensor chips
103f and 103g is broadened.
FIG. 2B is a graph illustrating broadening of an interval between
sensor chips. The horizontal axis indicates the position of an
interval between sensor chips 103 with a focus on one row of the
sensor array. Each row includes eight sensor chips 103, and thus
there are seven intervals. The vertical axis indicates a length of
an interval. A graph 202 indicates the length before the
scintillator panel is adhered to the sensor panel. A graph 203
indicates the intervals after the scintillator panel is adhered to
the sensor panel. As indicated in FIG. 2B, an interval between
adjacent sensor chips 103 at any position is broadened. In
addition, it is also indicated that the closer to an end of the
sensor array, the larger the degree of broadening. On the other
hand, in the radiation imaging apparatus 100, in a partial region
of the sensor array, two adjacent sensor chips 103 are bonded to
the sensor base 101 using separate bonding sheets 102. Such an
arrangement prevents positional shifts of the sensor chips 103.
The way of separation of the plurality of bonding sheets 102 is not
limited to the example of the radiation imaging apparatus 100. For
example, the plurality of bonding sheets 102 may also be separated
at a central position in the row direction. Specifically, a
configuration may also be adopted in which four sensor chips 103 on
the left side of each row are bonded using one bonding sheet 102,
and four sensor chips 103 on the right side are bonded using
another bonding sheet 102. The length of the one bonding sheet 102
in the row direction is shortened, and thus the intervals between
the sensor chips can be prevented from broadening. In the radiation
imaging apparatus 100, also in the column direction, in a partial
region of the sensor array, two adjacent sensor chips 103 are
bonded to the sensor base 101 using separate bonding sheets 102.
The number of sensor chips 103 aligned in the column direction is
small (two in this example), and thus such two sensor chips 103 may
be bonded using the same bonding sheet 102, in any region.
Second Embodiment
A configuration example of a radiation imaging apparatus 300
according to a second embodiment will be described with reference
to FIGS. 3A to 3C. FIG. 3A is a plan view of the radiation imaging
apparatus 300. FIG. 3B is a cross-sectional view cut across a line
C-C' in FIG. 3A. FIG. 3C is a cross-sectional view cut across a
line D-D' in FIG. 3A. In FIG. 3A, for convenience of description, a
bonding member 104, a scintillator layer 105, and a scintillator
base 106 are omitted. Differences from the radiation imaging
apparatus 100 will be mainly described below.
In the radiation imaging apparatus 300, a second sensor chip and a
third sensor chip from an end of the sensor array in each row of
the sensor array are bonded to the sensor base using separate
bonding sheets. Specifically, a second sensor chip 103b from the
end of the sensor array is bonded using a bonding sheet 102e, and a
third sensor chip 103h from the end of the sensor array is bonded
using a bonding sheet 102f Such an arrangement further prevents
position deviation of sensor chips 103.
Third Embodiment
A configuration example of a radiation imaging apparatus 400
according to a third embodiment will be described with reference to
FIGS. 4A to 4C. FIG. 4A is a plan view of the radiation imaging
apparatus 400. FIG. 4B is a cross-sectional view cut along a line
E-E' in FIG. 4A. FIG. 4C is a cross-sectional view cut along a line
F-F' in FIG. 4A. In FIG. 4A, for convenience of description, a
bonding member 104, a scintillator layer 105, and a scintillator
base 106 are omitted. Differences from the radiation imaging
apparatus 100 will be mainly described below.
In the radiation imaging apparatus 400, in the entire region of the
sensor array, two adjacent sensor chips 103 are bonded to the
sensor base 101 using separate bonding sheets 102. In other words,
the plurality of sensor chips 103 and the plurality of bonding
sheets 102 have one-to-one correspondence. Such an arrangement
further prevents position deviation of the sensor chips 103.
Fourth Embodiment
A configuration example of a radiation imaging apparatus 500
according to a fourth embodiment will be described with reference
to FIGS. 5A to 5C. FIG. 5A is a plan view of the radiation imaging
apparatus 500. FIG. 5B is a cross-sectional view cut along a line
G-G' in FIG. 5A. FIG. 5C is a cross-sectional view cut along a line
H-H' in FIG. 5A. In FIG. 5A, for convenience of description, a
bonding member 104, a scintillator layer 105, and a scintillator
base 106 are omitted. Differences from the radiation imaging
apparatus 100 will be mainly described below.
In the radiation imaging apparatus 500, on a side that faces an
adjacent sensor chip 103, out of the sides of a sensor chip bonded
to the sensor base 101 using a bonding sheet 102 that is separate
from that of the adjacent sensor chip 103, the outer periphery of
the bonding sheet 102 is positioned inward of that side.
Specifically, on a side 501 that faces an adjacent sensor chip
103b, out of the sides of a sensor chip 103a bonded using a bonding
sheet 102a that is separate from that of the sensor chip 103b, the
outer periphery of the bonding sheet 102a is positioned inward of
the side 501.
Even if the plurality of bonding sheets 102 are separated from each
other, when the scintillator panel is adhered, there is a
possibility that two adjacent bonding sheets 102 come into contact
with each other, and a state similar to that in FIG. 2A is entered,
depending on the material and size of the bonding sheets 102. In
view of this, in the radiation imaging apparatus 500, such contact
is suppressed by broadening an interval between two adjacent
bonding sheets 102. From among the sides of a sensor chip bonded to
the sensor base 101 using a bonding sheet 102 that is separate from
that of an adjacent sensor chip 103, on sides other than a side
that faces the adjacent sensor chip 103, the outer periphery of the
bonding sheet 102a may be inward or outward of that side. In the
radiation imaging apparatus 500, the outer periphery of the bonding
sheet 102a is inward of those sides as well.
Fifth Embodiment
A configuration example of a radiation imaging apparatus 600
according to a fifth embodiment will be described with reference to
FIG. 6A to 6C. FIG. 6A is a plan view of the radiation imaging
apparatus 600. FIG. 6B is a cross-sectional view cut along a line
I-I' in FIG. 6A. FIG. 6C is a cross-sectional view cut along a line
J-J' in FIG. 6A. In FIG. 6A, for convenience of description, a
bonding member 104, a scintillator layer 105, and a scintillator
base 106 are omitted. Differences from the radiation imaging
apparatus 100 will be mainly described below.
In the radiation imaging apparatus 600, at least some sensor chips
103 out of a plurality of sensor chips 103 have a side on which a
wiring member is arranged. In FIG. 6A, only some of the sensor
chips 103 have a wiring member 601, but, instead, all of the sensor
chips 103 may have the wiring member 601. The wiring member 601 is
a member for transmitting a signal from the sensor chip 103 to an
external apparatus. The wiring member 601 is, for example, an FPC
(flexible printed substrate).
A sensor chip 103a has the wiring member 601 on its side 602 that
is directed toward the outside of the sensor array, out of its two
shorter sides. On this side 602 on which the wiring member 601 is
arranged, a bonding sheet 102a may extend beyond an orthogonal
projection of an edge 603 of the scintillator layer 105 to the
outside of the sensor chip 103a. Here, on this side 602 on which
the wiring member 601 is arranged, the bonding sheet 102a extends
beyond the side 602 to the outside of the sensor chip 103a.
When bonding the sensor panel and scintillator panel, the sensor
chips 103 receive intense stress from the edge 603 of the
scintillator layer 105. In the radiation imaging apparatus 600, the
bonding sheet 102a supports the edge of the sensor chip 103 from
below on the side 602, and thus it is possible to suppress damage
of the sensor chip 103 due to this stress.
On the sides other than the side on which the wiring member 601 is
arranged, the outer periphery of the bonding sheet 102a may be
inward or outward of those sides. In the radiation imaging
apparatus 600, similarly to the radiation imaging apparatus 500,
the outer periphery of the bonding sheet 102a is inward of those
sides.
Sixth Embodiment
A configuration example of a radiation imaging apparatus 700
according to a sixth embodiment will be described with reference to
FIGS. 7A to 7C. FIG. 7A is a plan view of the radiation imaging
apparatus 700. FIG. 7B is a cross-sectional view cut along a line
K-K' in FIG. 7A. FIG. 7C is a cross-sectional view cut along a line
L-L' in FIG. 7A. In FIG. 7A, for convenience of description, a
bonding member 104, a scintillator layer 105, and a scintillator
base 106 are omitted. Differences from the radiation imaging
apparatus 100 will be mainly described below.
In the radiation imaging apparatus 700, the bonding member 104 is
formed of a hot melt material, for example, a hot melt sheet. The
hot melt material refers to a material that has a property of
exhibiting adhesion force when heated. The viscosity of the hot
melt sheet decreases by being heated, and thus, as shown in FIGS.
7B and 7C, the bonding member 104 enters spaces between the sensor
chips 103. As a result, the adhesive force of the bonding member
104 to the sensor chips 103 improves.
The transparency of the hot melt sheet may be, for example, 90% or
higher in the vicinity of 550 nm, which is a peak emission
wavelength of CsI:Tl. In addition, the thickness of the hot melt
sheet may be about 10 to 100 from the viewpoint of prevention of
deterioration in the MTF and prevention of damage due to an
extraneous material that enters the space between the scintillator
layer 105 and sensor chips 103.
When a hot melt sheet is used as the bonding member 104, the sensor
panel and the scintillator panel are bonded to each other by
performing heat pressure bonding using a laminating machine capable
of heating. When performing heat pressure bonding in this manner,
the viscosity of the bonding sheet 102 also decreases, and some of
the bonding sheets 102 easily enter spaces between sensor chips
103. Even in this case, by bonding the plurality of sensor chips
103 using the plurality of bonding sheets 102 separated from each
other, positional shifts of the sensor chips 103 can be
suppressed.
Other Embodiments
FIG. 8 is a diagram showing an example in which the radiation
imaging apparatus according to the present invention is applied to
an X-ray diagnosis system (radiation imaging system). An X-ray 6060
(radiation) generated in an X-ray tube 6050 (radiation source)
passes through a chest 6062 of a test subject or a patient 6061,
and is incident on a radiation imaging apparatus 6040. The
radiation imaging apparatus 6040 may be any of the radiation
imaging apparatuses of the above embodiments. This incident X-ray
includes information regarding the internal body of the patient
6061. The scintillator emits light in response to incidence of an
X-ray, and this light is subjected to photoelectric conversion, and
electrical information is acquired. This information is converted
into digital signals, which are subjected to image processing by an
image processor 6070, which is a signal processing unit, and can be
observed on a display 6080 that is a display unit of a control
chamber. Note that the radiation imaging system at least has a
radiation imaging apparatus, and a signal processing unit that
processes a signal from the radiation imaging apparatus.
In addition, this information can be transferred to a remote
location by a transmission processing unit such as a phone line
6090, and can be displayed on a display 6081 (display unit) of a
doctor's office or the like in another location or can be stored to
an optical disk or the like (recording unit), and can be used for a
medical practitioner in a remote location to make a diagnosis. It
is also possible to record this information to a film 6110
(recording medium) by a film processor 6100 (recording unit).
While the present invention has been described with reference to
exemplary embodiments, it is to be understood that the invention is
not limited to the disclosed exemplary embodiments. The scope of
the following claims is to be accorded the broadest interpretation
so as to encompass all such modifications and equivalent structures
and functions.
This application claims the benefit of Japanese Patent Application
No. 2018-138015, filed Jul. 23, 2018 which is hereby incorporated
by reference herein in its entirety.
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